Sealing peg



May 5, 1959 c. F. FISHER SEALING PEG Filed March 20, 1958 INVENTORCLAUDE F. FISHER ATTORNEY United States Patent SEALING PEG Claude F.Fisher, Jersey Shore, Pa., assignor to Sylvania Ellectric Products Inc.,a corporation of Massac usetts I Application March 20, 1958, Serial No.722,729

' 6 Claims. (Cl. 49-2 The invention relates to scaling pegs such as areutilized in electronic tube manufacturing machinery to seal abulb orenvelope to a base portion which supports the electrodes. Moreparticularly, the invention relates to a sealing machine having sealingpegs, the pegs being adaptable to various sizes of bulbs and baseportions.

It is common practice, at the present time, to use a single bulb to baseportion (or stem) sealing machine for various types of bulbs and stemswhich have like diametered stems and bulbs. However when production ischanged from one type of tube to another where the size of the bulb orthe size of the stem is changed, it is necessary to remove all of thesealing pegs from the machine and replace them by others which wouldsuit the requirements of the new sizedbulb or the new sized stem.

It is an obejct of this invention to provide a sealing peg that can beutilized with at least two different diametered envelopes ortwoditferent 'diametered stems.

This and other objects of the invention will be better understood afterconsideration of the following specification when taken in conjunctionwith the accompanying drawing in which:

Fig. l is a pictorial view of a new sealing peg and made in accordancewith the invention, and also associated parts, the view showing anadjustable peg with a sleeve in an upper operative bulb supportingposition.

Fig. 2 is a view of the new sealing peg with the sleeve in aninoperative lower position.

Fig. 3 is a perspective view of an inner post forming part of thesealing peg.

Fig. 4 is a view of the sleeve which is slidable along the post andwhich forms another part of the sealing peg and Fig. 5 is a view of theelectron bulb itself when formed on a peg of the character disclosedherein.

The sealing peg of this invention may be utilized in a bulb to stemsealing machine such as is shown and described in the patent to Gartner2,661,576.

In Fig. 1 of the instant disclosure there is shown a sealing peggenerally indicated at 10, a glass stem 12 with its attached mount 14resting on the peg, and a glass bulb 16 also supported by the peg. Thebulb is held in vertical position by positioning fingers18 with the bulbready to be sealed, at its skirt portion, to the stem. There is alsoshown burners 20 with their fires directed at the skirt portion of thebulb.

As the peg with the supporting positioning fingers is rotated before theburners, the glass in the bulb will be softened while the glass stemwill become heated; gradually the glass at the bottom of the bulb willbe shrunk in diameter, the length of the bulb will decrease and finallythe bottom of the bulb will fuse with the rim of the glass stem.Depending on the relative diameters of the stem and of the bulb, i.e. onthe space between the interior of the bulb wall and periphery of thestem, there must be initially a definite amount of glass below the levelof the area where the bulb and stem are joined; the greater the spacingthe more glass is initially required in the skirt portion of the bulbbelow the joint level. To determine the length of the skirt portion, thesealing peg is made with two sets of supporting ears 22 and 24. With asmall clearance between the bulb and the stem the tops of the cars 24,which tops are all in a common horizontal plane, extend above the ears22 and support the bottom of the bulb as shown in Fig. 1. Wth a largerclearance between the bulb and the stem, the cars 24 are below the levelof the tops of the ears 22, as shown in Fig. 2, and the cars 22, whosetops are also in a common horizontal plane, then support the bulb withthe skirt portion of the bulb extending farther below ethe stem than inthe case of Fig. 1, allowing more glass for bridging the space betweenbulb and stem.

The following construction is employed to support the ears 22 and 24:The sealing peg has an inner' post 26, shown in Fig. 3, and an outersleeve 28 shown in Fig. 4. The post has a base 30 which is mounted inany convenient fashion, as by set screw 32, onto a rod 34 verticallyslidable in the turret of the sealing machine, in a manner similar tothat shown in the Gartner patent. Above the base 30, the post is reducedin diameter to form a column as indicated at 36 and is surmounted by anintegral stem and bulb support 38. The support 38 is verticallyperforated or bored, as at 40, with the circle diameter of the boresgreater than the diameter of the column,

- to allow the leads of a stem to extend downwardly through the supportand about the exterior of the column. The support 38 is further providedwith 3 equally spaced cars 22 on which the bottom of a bulb may bebrought to rest. The top surface of the ears 22 is at a fixed elevationrelative tothe top surface of the stem support so that a definite amountof glass will project down below the level of the stem placed on thestem support for a given set of stem and bulb.

Slidable on the inner post 26 is the sleeve 28, this sleeve beingprovided with set screws 42 only one of which is shown in Fig. 2. Thissleeve has a lower skirt portion 44 slidable on the base 30, the lowerlimit of sliding being limited by a pin 46 set into the base. The upperend 48 of the sleeve surrounds the support 38 and is provided with threeequally spaced upstanding ears 24 intercalated with the ears 22. Theupper faces of the ears 24 extend above the level of the upper faces ofears 22 when the sleeve is raised to its maximum height with the upperface of the upper end of the sleeve in engagement with the under facesof cars 22. When a bulb and stem are utilized with a comparatively smallspacing between the two, the bottom of the bulb is positioned on the nowraised cars 24, since less glass will be required to properly fuse thebulb and stem together. The sleeve is cut out between the portions 44and 48, as indicated at 50, to allow for ease in clearing out the pegholes 40, should that be necessary.

What is claimed is:

1. A sealing peg having an inner member carrying a stem support at itsupper end, said stem support having laterally extending ears to supporta bulb, a sleeve slidable on said inner member below the stem supportwith means to secure the sleeve at a selected height on the innermember, and ears on said sleeve adapted to extend above the level ofsaid first ears to support the bulb when the sleeve is in an upperposition.

2. A sealing peg having an inner member carrying a stem support at itsupper end, said stem support having laterally extending ears to supporta bulb, a sleeve slidable between limits on said inner member below thestern support with means to secure the sleeve at a selected height onthe the inner member intermediate and at said limits, and ears on saidsleeve adapted to extend above the level of said first ears to supportthe bulb when the sleeve is in an upper position.

3. A sealing peg having an inner member carrying a stem support at itsupper end, said stem support having laterally extending ears to supporta bulb, a sleeve slidable on said inner member below the stem supportwith means to secure the sleeve at- 21 selected height on the innermember, and ears on said sleeve inposition adapted to be intercalatedwith said first ears and to extend above the level ofsaid first ears tosupport the bulb when the sleeve is in an upper position.

4. A sealing peg comprising an inner member having a: cylindrical basefor attachment to a vertically reciprocatablerod, a column of smallerdiameter than said base and-coaxial therewith extending upwardly fromsaid base, and a support integral with said column at the upper endthereof, said support having vertical bores therethrough in a circlediameter greater than the diameter of said column to receive the leadsof a stem, said support also having radially extending ears whose topsurfaces are in a common plane to support the bottom edge of a bulb tobe sealed to the stem; a sleeve surrounding the inner member, means-tofasten the sleeve to said inner member at a selected elevation,additional ears on said sleeve with the top surfaces of said additionalears in a common plane, said additional ears being of a heightsufiicient to protrude above the ears onthe support when the sleeve isin an upper position and to lie at or below the level of the tops of theears on the support when the sleeve is in alower position.

5, A sealing peg comprising an inner member having a cylindrical basefor attachment to a vertically reciprocatable rod, a column of smallerdiameter than said base and coaxial therewith extending upwardly fromsaid base, and a support integral with said column at the upper end:thereof, said support having vertical bores therethrough in a circlediameter greater than the diameter 3:)

of said column to receive the leads of a stem, said support also havingradially extending ears to support the bottom edge of a bulb to besealed to the stem; a sleeve surrounding the inner member, means tofasten the sleeve to said inner member at a selected elevation andadditional ears on said sleeve, said additional ears being of a heightsufficient to protrude above the tops of the ears on the support whenthe sleeve is in an upper position and to lie at or below the level ofthe tops of the ears on the support when the sleeve is in a lowerposition; and means to limit the downward motion of the" sleeve relativetothe inner support.

6. A sealing peg comprising an inner member having a cylindrical basefor attachment to a vertically reciprocatable rod, a column of smallerdiameter than said base and coaxial therewith extending upwardly fromsaid base, and a support integral with said column at the upper endthereof, said support having vertical bores therethrough in a circlediameter greater than the diameter of said column toreceive the leads ofa stem, said support also having radially extending ears to supportthebottom edge of a bulb to be sealed to the stem; a sleeve surrounding theinner member, means to fasten the sleeve to said inner member at aselected elevation, and additional ears on said sleeve, said additional?ears being of a height sufficient to protrude above the tops of the earson the sup port when the sleeve is in an upper position and to lie at orbelow the level of the tops of the ears on the support when the sleeveis in a lower position; and 21 cut out in said sleeve to provide accessto the space withinthe sleeve for facilitating cleaning. out the boresin the support.

References Cited in the file of this patent UNITED STATES PATENTS2,413,766 Honzl Ian. 7, 1947

